The present invention relates to image sensors and, more particularly, to imaging devices with image sensors that may be used to produce high-dynamic-range images in a global shutter configuration.
Image sensors are commonly used in electronic devices such as cellular telephones, cameras, and computers to capture images. In a typical arrangement, an electronic device is provided with a single image sensor and a single corresponding lens. Some electronic devices use arrays of image sensors.
In certain applications, such as when acquiring still or video images of a scene with a large range of light intensities, it may be desirable to capture high-dynamic range images. While highlight and shadow detail may be lost using a conventional image sensor, highlight and shadow detail may be retained using image sensors with high-dynamic-range capabilities.
For applications in which images are captured using a non-stationary imaging device (i.e. an imaging device in a moving automobile), it may be desirable to capture images with a global shutter scheme. A moving imaging device that uses a rolling shutter scheme may undesirably capture an image that is distorted or skewed. Images captured using the global shutter scheme are not distorted or skewed. The global shutter scheme requires additional storage in the imaging sensor. Additional storage in the imaging sensor requires physical space which reduces the available space for photosensitive elements. This may reduce the efficiency of the imaging sensor.
It would therefore be desirable to be able to provide imaging devices that use the global shutter scheme with improved dynamic range capabilities.